I Always Feel Like Someone Is Watching Me :: Symblogogy

Eyebox2 - The system uses an array of infrared LEDs and a 1.3 megapixel digital camera to monitor eye movements. The camera has higher resolution than most eye-tracking systems, and can easily pick out the distinctive infrared signature from a pair of human pupils from up to 10 metres. It can also track several people at once and can determine their gaze from four metres away to within 15 degrees. Image Credit: New Scientist